Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 72
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Cancer Immunol Immunother ; 73(2): 34, 2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38280067

RESUMO

Immune checkpoint inhibitors (ICIs) have demonstrated efficacy and improved survival in a growing number of cancers. Despite their success, ICIs are associated with immune-related adverse events that can interfere with their use. Therefore, safer approaches are needed. CD6, expressed by T-lymphocytes and human NK cells, engages in cell-cell interactions by binding to its ligands CD166 (ALCAM) and CD318 (CDCP1). CD6 is a target protein for regulating immune responses and is required for the development of several mouse models of autoimmunity. Interestingly, CD6 is exclusively expressed on immune cells while CD318 is strongly expressed on most cancers. Here we demonstrate that disrupting the CD6-CD318 axis with UMCD6, an anti-CD6 monoclonal antibody, prolongs survival of mice in xenograft mouse models of human breast and prostate cancer, treated with infusions of human lymphocytes. Analysis of tumor-infiltrating immune cells showed that augmentation of lymphocyte cytotoxicity by UMCD6 is due to effects of this antibody on NK, NKT and CD8 + T cells. In particular, tumor-infiltrating cytotoxic lymphocytes from UMCD6-treated mice expressed higher levels of perforin and were found in higher proportions than those from IgG-treated mice. Moreover, RNA-seq analysis of human NK-92 cells treated with UMCD6 revealed that UMCD6 up-regulates the NKG2D-DAP10 receptor complex, important in NK cell activation, as well as its downstream target PI3K. Our results now describe the phenotypic changes that occur on immune cells upon treatment with UMCD6 and further confirm that the CD6-CD318 axis can regulate the activation state of cytotoxic lymphocytes and their positioning within the tumor microenvironment.


Assuntos
Antineoplásicos , Neoplasias , Animais , Humanos , Camundongos , Anticorpos Monoclonais/farmacologia , Antígenos CD , Antígenos de Diferenciação de Linfócitos T/metabolismo , Antígenos de Neoplasias , Moléculas de Adesão Celular , Linfócitos/metabolismo , Microambiente Tumoral
2.
Mol Plant Microbe Interact ; 36(7): 452-456, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36802869

RESUMO

Bipolaris sorokiniana, one of the most devastating hemibiotrophic fungal pathogens, causes root rot, crown rot, leaf blotching, and black embryos of gramineous crops worldwide, posing a serious threat to global food security. However, the host-pathogen interaction mechanism between B. sorokiniana and wheat remains poorly understood. To facilitate related studies, we sequenced and assembled the genome of B. sorokiniana LK93. Nanopore long reads and next generation sequencing short reads were applied in the genome assembly, and the final 36.4-Mb genome assembly contains 16 contigs with the contig N50 of 2.3 Mb. Subsequently, we annotated 11,811 protein-coding genes. Of these, 10,620 were functional genes, 258 of which were identified as secretory proteins, including 211 predicted effectors. Additionally, the 111,581-bp mitogenome of LK93 was assembled and annotated. The LK93 genomes presented in this study will facilitate research in the B. sorokiniana-wheat pathosystem for better control of crop diseases. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.


Assuntos
Ascomicetos , Genoma Mitocondrial , Ascomicetos/genética , Triticum/microbiologia , Genoma Mitocondrial/genética , Bipolaris/genética , Doenças das Plantas/microbiologia
3.
Ecotoxicol Environ Saf ; 262: 115128, 2023 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-37315361

RESUMO

Rare earth elements (REEs) have been widely used in traditional and high-tech fields, and high doses of REEs are considered a risk to the ecosystem. Although the influence of arbuscular mycorrhizal fungi (AMF) in promoting host resistance to heavy metal (HM) stress has been well documented, the molecular mechanism by which AMF symbiosis enhances plant tolerance to REEs is still unclear. A pot experiment was conducted to investigate the molecular mechanism by which the AMF Claroideoglomus etunicatum promotes maize (Zea mays) seedling tolerance to lanthanum (La) stress (100 mg·kg-1 La). C. etunicatum symbiosis significantly improved maize seedling growth, P and La uptake and photosynthesis. Transcriptome, proteome, and metabolome analyses performed alone and together revealed that differentially expressed genes (DEGs) related to auxin /indole-3-acetic acid (AUX/IAA) and the DEGs and differentially expressed proteins (DEPs) related to ATP-binding cassette (ABC) transporters, natural resistance-associated macrophage proteins (Nramp6), vacuoles and vesicles were upregulated. In contrast, photosynthesis-related DEGs and DEPs were downregulated, and 1-phosphatidyl-1D-myo-inositol 3-phosphate (PI(3)P) was more abundant under C. etunicatum symbiosis. C. etunicatum symbiosis can promote plant growth by increasing P uptake, regulating plant hormone signal transduction, photosynthesis and glycerophospholipid metabolism pathways and enhancing La transport and compartmentalization in vacuoles and vesicles. The results provide new insights into the promotion of plant REE tolerance by AMF symbiosis and the possibility of utilizing AMF-maize interactions in REE phytoremediation and recycling.

4.
Int J Mol Sci ; 24(13)2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37446163

RESUMO

Fusarium pseudograminearum is one of the major fungal pathogens that cause Fusarium crown rot (FCR) worldwide and can lead to a substantially reduced grain yield and quality. Transcription factors play an important role in regulating growth and pathogenicity in plant pathogens. In this study, we identified a putative Zn(II)2Cys6 fungal-type domain-containing transcription factor and named it FpUme18. The expression of FpUME18 was induced during the infection of wheat by F. pseudograminearum. The ΔFpume18 deletion mutant showed defects in growth, conidial production, and conidial germination. In the responses to the cell wall, salt and oxidative stresses, the ΔFpume18 mutant inhibited the rate of mycelial growth at a higher rate compared with the wild type. The staining of conidia and mycelia with lipophilic dye FM4-64 revealed a delay in endocytosis when FpUME18 was deleted. FpUME18 also positively regulated the expression of phospholipid-related synthesis genes. The deletion of FpUME18 attenuated the pathogenicity of wheat coleoptiles. FpUME18 also participated in the production of the DON toxin by regulating the expression of TRI genes. Collectively, FpUme18 is required for vegetative growth, conidiation, stress response, endocytosis, and full virulence in F. pseudograminearum.


Assuntos
Fusarium , Parede Celular/genética , Endocitose/genética , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Fusarium/genética , Fusarium/patogenicidade , Regulação Fúngica da Expressão Gênica/genética , Doenças das Plantas/microbiologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Virulência/genética , Esporos Fúngicos/genética , Deleção de Sequência/genética
5.
Biochem Genet ; 60(5): 1601-1614, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35064361

RESUMO

Homeobox transcription factors have been implicated in filamentous growth, conidia formation and virulence in fungal pathogens. However, the presence of the homeobox gene family and their potential influence on pathogenesis in Fusarium pseudograminearum have not been investigated. F. pseudograminearum is an important plant pathogen that causes wheat and barley crown rot. In this study, we performed a genome-wide survey for F. pseudograminearum homeobox genes, and 11 FpHtfs were identified and characterized. Domain analyses revealed that all of these proteins contain a complete homeobox domain that contains three helices. Expression profiles of FpHtf genes at different pathogen stages showed that six FpHtf genes were induced during infection. Further, we generated and characterized FpHtf3 deletion mutants in F. pseudograminearum, showing it was essential for virulence. These results indicated that members of the homeobox gene family are likely involved in F. pseudograminearum pathogenicity. Our work also provides a useful foundation for further studies on the complexity and function of the homeobox gene family in F. pseudograminearum.


Assuntos
Fusarium , Genes Homeobox , Fusarium/genética , Fusarium/metabolismo , Doenças das Plantas/microbiologia , Virulência/genética
6.
Am J Physiol Gastrointest Liver Physiol ; 321(6): G668-G681, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34643097

RESUMO

MicroRNA-mediated regulation is critical for the proper development and function of the small intestinal (SI) epithelium. However, it is not known which microRNAs are expressed in each of the cell types of the SI epithelium. To bridge this important knowledge gap, we performed comprehensive microRNA profiling in all major cell types of the mouse SI epithelium. We used flow cytometry and fluorescence-activated cell sorting with multiple reporter mouse models to isolate intestinal stem cells, enterocytes, goblet cells, Paneth cells, enteroendocrine cells, tuft cells, and secretory progenitors. We then subjected these cell populations to small RNA-sequencing. The resulting atlas revealed highly enriched microRNA markers for almost every major cell type (https://sethupathy-lab.shinyapps.io/SI_miRNA/). Several of these lineage-enriched microRNAs (LEMs) were observed to be embedded in annotated host genes. We used chromatin-run-on sequencing to determine which of these LEMs are likely cotranscribed with their host genes. We then performed single-cell RNA-sequencing to define the cell type specificity of the host genes and embedded LEMs. We observed that the two most enriched microRNAs in secretory progenitors are miR-1224 and miR-672, the latter of which we found is deleted in hominin species. Finally, using several in vivo models, we established that miR-152 is a Paneth cell-specific microRNA.NEW & NOTEWORTHY In this study, first, microRNA atlas (and searchable web server) across all major small intestinal epithelial cell types is presented. We have demonstrated microRNAs that uniquely mark several lineages, including enteroendocrine and tuft. Identification of a key marker of mouse secretory progenitor cells, miR-672, which we show is deleted in humans. We have used several in vivo models to establish miR-152 as a specific marker of Paneth cells, which are highly understudied in terms of microRNAs.


Assuntos
Linhagem da Célula , Células Epiteliais/metabolismo , Perfilação da Expressão Gênica , Mucosa Intestinal/metabolismo , Intestino Delgado/metabolismo , MicroRNAs/genética , Transcriptoma , Animais , Biomarcadores/metabolismo , Separação Celular , Células Cultivadas , Biologia Computacional , Cães , Feminino , Citometria de Fluxo , Mucosa Intestinal/citologia , Intestino Delgado/citologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , MicroRNAs/metabolismo , Organoides , RNA-Seq , Análise de Célula Única
7.
Curr Genet ; 66(3): 507-515, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31696258

RESUMO

Fusarium pseudograminearum is an important pathogen of Fusarium crown rot and Fusarium head blight, which is able to infect wheat and barley worldwide, causing great economic losses. Transcription factors (TFs) of the basic leucine zipper (bZIP) protein family control important processes in all eukaryotes. In this study, we identified a gene, designated FpAda1, encoding a bZIP TF in F. pseudograminearum. The homolog of FpAda1 is also known to affect hyphal growth in Neurospora crassa. Deletion of FpAda1 in F. pseudograminearum resulted in defects in hyphal growth, mycelial branching and conidia formation. Pathogenicity assays showed that virulence of the Δfpada1 mutant was dramatically decreased on wheat coleoptiles and barley leaves. However, wheat coleoptile inoculation assay showed that Δfpada1 could penetrate and proliferate in wheat cells. Moreover, the FpAda1 was required for abnormal nuclear morphology in conidia and transcription of FpCdc2 and FpCdc42. Taken together, these results indicate that FpAda1 is an important transcription factor involved in growth and development in F. pseudograminearum.


Assuntos
Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Proteínas Fúngicas/metabolismo , Fusarium/crescimento & desenvolvimento , Hordeum/microbiologia , Doenças das Plantas/microbiologia , Esporos Fúngicos/crescimento & desenvolvimento , Triticum/microbiologia , Fatores de Transcrição de Zíper de Leucina Básica/genética , Proteínas Fúngicas/genética , Fusarium/genética , Fusarium/patogenicidade , Folhas de Planta/microbiologia , Esporos Fúngicos/genética
8.
Curr Genet ; 66(1): 229-243, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31312935

RESUMO

Fusarium pseudograminearum-induced crown rot causes significant reduction to wheat production worldwide. To date, efforts to develop effective resistance to this disease have been hampered by the quantitative nature of resistance trait and a lack of understanding of the molecular pathogenesis. Non-ribosomal peptides have important roles in development, pathogenicity, and toxins in many plant pathogens, while less is known in F. pseudograminearum. In this work, we studied the expression and function of a nonribosomal peptide gene FpNPS9 in F. pseudograminearum. We determined the expression of FpNPS9 which was significantly up regulated during the infection of wheat. A deletion mutant Δfpnps9 produced in this study displayed a normal growth and conidiation phenotype, however, hyphae polar growth was obviously affected. Deoxynivalenol production in this mutant was significantly reduced and the infection of wheat coleoptiles and wheat spikelet was attenuated. The Δfpnps9 showed serious defects on the extension of infectious hyphae in plant and inhibition of roots elongation compared with the wild type. The complementation assay using a FpNPS9-GFP fusion construct fully restored the defects of the mutant. GFP signal was detected in the germinating conidia and infectious hyphae in coleoptiles of the infected plants. Interestingly, the signal was not observed when it was grown on culture medium, suggesting that the expression of FpNPS9 was regulated by an unknown host factor. This observation was supported by the result of qRT-PCR. In summary, we provided new knowledge on FpNPS9 expression in F. pseudograminearum and its function in F. pseudograminearum pathogenicity in wheat.


Assuntos
Proteínas Fúngicas/genética , Fusarium/genética , Proteínas Nucleares/genética , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Triticum/genética , Triticum/microbiologia , Deleção de Genes , Expressão Gênica , Técnicas de Silenciamento de Genes , Recombinação Homóloga
9.
Fungal Genet Biol ; 135: 103299, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31706014

RESUMO

Histone deacetylases (HDACs) play essential roles in modulating chromatin structure to provide accessibility to gene regulators. Increasing evidence has linked HADCs to pathogenesis control in the filamentous plant fungi. However, its function remains unclear in Fusarium pseudograminearum, which has led to the emergence of the disease Fusarium crown rot in China. Here we identified the FpDEP1 gene, an orthologue of Saccharomyces cerevisiae DEP1 encoding a component of the Rpd3 histone deacetylase complex in F. pseudograminearum. The gene deletion mutant, ΔFpdep1, showed significantly retarded growth on PDA plates with reduced aerial hyphae formation. Pathogenicity tests displayed no typical leaf lesions and limited expansion capability of coleoptiles. Histopathological analysis indicated the ΔFpdep1 deletion mutant differentiated infectious hyphae and triggered massive reactive oxygen species (ROS) accumulation during the early infection stage, resulting in limited expansion to neighbor cells which was concurring with sensitivity to H2O2 and SDS tests in vitro. FM4-64 staining revealed that the ΔFpdep1 deletion mutant was delayed in endocytosis. The FpDEP1-GFP transgene complemented the mutant phenotypes and the fusion protein co-localized with DAPI staining, indicating that the FpDEP1 gene product is localized to the nucleus in spores and mycelia. Immunoprecipitation coupled with LC-MS/MS and yeast two-hybrid screening identified the Rpd3L-like HDAC complex containing at least FpDep1, FpSds3, FpSin3, FpRpd3, FpRxt3, FpCti6, FpRho23, and FpUme6. These results suggest that FpDep1 is involved in a HDAC complex functioning on fungal development and pathogenesis in F. pseudograminearum.


Assuntos
Proteínas Fúngicas/genética , Fusarium/genética , Fusarium/patogenicidade , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , China , Proteínas Fúngicas/metabolismo , Fusarium/enzimologia , Histona Desacetilases/classificação , Hordeum/microbiologia , Peróxido de Hidrogênio/metabolismo , Hifas/crescimento & desenvolvimento , Doenças das Plantas/microbiologia , Folhas de Planta/microbiologia , Saccharomyces cerevisiae/genética , Triticum/microbiologia , Virulência
10.
Environ Microbiol ; 21(8): 2740-2754, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30897256

RESUMO

To investigate the distribution and diversity of the pathogens associated with Fusarium crown rot in the Huanghuai wheat-growing region (HHWGR) of China, we collected wheat samples with symptomatic stem bases from seven provinces in the HHWGR between 2013 and 2016. A total of 1196 isolates obtained from 222 locations were identified as 9 Fusarium species based on morphological and molecular identification. Of these pathogen species, F. pseudograminearum was the dominant species. Furthermore, F. sinensis was isolated from the disease specimens and tested for virulence to wheat. The result of the pathogenicity revealed that an intraspecific differentiation existed in F. pseudograminearum; sequence analysis of the EF-1α gene showed that 194 F. pseudograminearum isolates were differentiated into two distinct clades which closed to the strains from Australia and China respectively, but neither pathogenicity nor EF-1α sequence was related to the geographic origins of these isolates. However, universal rice primers-polymerase chain reaction showed a correlation with the geographical origins of the 194 isolates, which were divided into eight subclusters, the level of genetic diversity was higher within a geographical population than among the different populations. The results of these analyses can be directly used to facilitate disease monitoring and development of control strategies.


Assuntos
Fusarium/genética , Doenças das Plantas/microbiologia , Triticum/microbiologia , China , Variação Genética , Reação em Cadeia da Polimerase , Virulência
11.
J Biol Chem ; 292(7): 2586-2600, 2017 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-28053090

RESUMO

Gut microbiota play an important role in regulating the development of the host immune system, metabolic rate, and at times, disease pathogenesis. The factors and mechanisms that mediate interactions between microbiota and the intestinal epithelium are not fully understood. We provide novel evidence that microbiota may control intestinal epithelial stem cell (IESC) proliferation in part through microRNAs (miRNAs). We demonstrate that miRNA profiles differ dramatically across functionally distinct cell types of the mouse jejunal intestinal epithelium and that miRNAs respond to microbiota in a highly cell type-specific manner. Importantly, we also show that miRNAs in IESCs are more prominently regulated by microbiota compared with miRNAs in any other intestinal epithelial cell subtype. We identify miR-375 as one miRNA that is significantly suppressed by the presence of microbiota in IESCs. Using a novel method to knockdown gene and miRNA expression ex vivo enteroids, we demonstrate that we can knock down gene expression in Lgr5+ IESCs. Furthermore, when we knock down miR-375 in IESCs, we observe significantly increased proliferative capacity. Understanding the mechanisms by which microbiota regulate miRNA expression in IESCs and other intestinal epithelial cell subtypes will elucidate a critical molecular network that controls intestinal homeostasis and, given the heightened interest in miRNA-based therapies, may offer novel therapeutic strategies in the treatment of gastrointestinal diseases associated with altered IESC function.


Assuntos
Mucosa Intestinal/metabolismo , Células-Tronco/microbiologia , Transcriptoma , Animais , Feminino , Vida Livre de Germes , Proteínas de Fluorescência Verde/genética , Mucosa Intestinal/citologia , Mucosa Intestinal/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Fatores de Transcrição SOX9/genética , Células-Tronco/citologia
12.
BMC Cell Biol ; 19(1): 15, 2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-30111276

RESUMO

BACKGROUND: Conditional reprogramming has enabled the development of long-lived, normal epithelial cell lines from mice and humans by in vitro culture with ROCK inhibitor on a feeder layer. We applied this technology to mouse small intestine to create 2D mouse intestinal epithelial monolayers (IEC monolayers) from genetic mouse models for functional analysis. RESULTS: IEC monolayers form epithelial colonies that proliferate on a feeder cell layer and are able to maintain their genotype over long-term passage. IEC monolayers form 3D spheroids in matrigel culture and monolayers on transwell inserts making them useful for functional analyses. IEC monolayers derived from the Cystic Fibrosis (CF) mouse model CFTR ∆F508 fail to respond to CFTR activator forskolin in 3D matrigel culture as measured by spheroid swelling and transwell monolayer culture via Ussing chamber electrophysiology. Tumor IEC monolayers generated from the ApcMin/+ mouse intestinal cancer model grow more quickly than wild-type (WT) IEC monolayers both on feeders and as spheroids in matrigel culture. CONCLUSIONS: These results indicate that generation of IEC monolayers is a useful model system for growing large numbers of genotype-specific mouse intestinal epithelial cells that may be used in functional studies to examine molecular mechanisms of disease and to identify and assess novel therapeutic compounds.


Assuntos
Células Epiteliais/citologia , Intestinos/citologia , Organoides/citologia , Células 3T3 , Polipose Adenomatosa do Colo/metabolismo , Polipose Adenomatosa do Colo/patologia , Alelos , Animais , Proliferação de Células , Autorrenovação Celular , Forma Celular , Células Cultivadas , Reprogramação Celular , Fibrose Cística/metabolismo , Fibrose Cística/patologia , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Células Epiteliais/metabolismo , Mucosa Intestinal/citologia , Camundongos , Camundongos Endogâmicos C57BL , Mutação/genética
13.
J Opt Soc Am A Opt Image Sci Vis ; 35(7): 1204-1211, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30110313

RESUMO

In wireless optical communication systems, the coherent detection scheme suffers severe performance degradation due to the phase fluctuation and polarization offset. To deal with such challenges, we propose a polarization coherent optical communication scheme with adaptive polarization control (PCPC), where the transmitted continuous-wave light is split into two paths-the binary phase shift keying modulated signal light and the reference light-which are orthogonally polarized and combined before being sent to free space. In the receiving site, the interference between the two lights can effectively suppress the atmospheric turbulence-induced phase fluctuation. Furthermore, we propose an adaptive polarization control scheme for eliminating the polarization offset caused by the transceiver misalignment and the atmospheric turbulence. Performance evaluation of the PCPC scheme with analytical expressions and numerical simulations shows that the PCPC scheme can effectively suppress the phase fluctuation without phase-locked loop and phase tracking algorithm; thus, the PCPC scheme outperforms the traditional coherent modulation in the turbulence channel. An elaborate designed indoor experiment was implemented to verify the scheme performance, where the measured residual phase fluctuation and measured residual polarization offset are both very small, and the experimental bit error rate performance can conform closely to the theory.

14.
Mol Imaging ; 16: 1536012117729044, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28884622

RESUMO

BACKGROUND: Near-infrared fluorescence (NIRF) imaging combined with enzyme-activatable NIRF probes has yielded promising results in cancer detection. OBJECTIVE: To test whether 3-dimensional (3-D) noninvasive in vivo NIRF imaging can detect effects of epidermal growth factor receptor (EGFR) inhibitor on both polypoid and flat tumor load in azoxymethane (AOM)-induced colon tumors or tumors in ApcMin/+ mice. METHODS: The AOM-injected KK-HIJ mice received EGFR inhibitor diet or chow diet. These and ApcMin/+ mice were given cathepsin-activatable probes (ProSense 680) before imaging. In vivo imaging was performed using quantitative tomographic NIRF imaging. Ex vivo imaging and histologic examination were performed. Dual imaging by micro computed tomography (CT) and 3D NIRF imaging was used to verify tumor location. RESULTS: Tumor load reduction by EGFR inhibition was detected ex vivo using cathepsin B probes. In vivo imaging revealed intense activation of probes only in large tumors. Dual imaging with microCT and 3D NIRF imaging improved tumor detection in vivo. CONCLUSIONS: The 3-D NIRF imaging with ProSense 680 can detect and quantify drug effects on colon tumors ex vivo. The NIRF imaging with ProSense 680 probe has limitations as a valid nonendoscopic method for intestinal tumor detection. Combing with other imaging modalities will improve the specificity and sensitivity of intestinal tumor detection in vivo.


Assuntos
Carcinogênese/patologia , Neoplasias do Colo/diagnóstico por imagem , Receptores ErbB/antagonistas & inibidores , Corantes Fluorescentes/química , Raios Infravermelhos , Adenoma/diagnóstico por imagem , Adenoma/patologia , Animais , Azoximetano , Catepsinas/metabolismo , Agregação Celular , Neoplasias do Colo/patologia , Dieta , Receptores ErbB/metabolismo , Imageamento Tridimensional , Linfócitos/patologia , Camundongos , Imagem Molecular , Microtomografia por Raio-X
15.
Opt Express ; 25(20): 24425-24436, 2017 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-29041387

RESUMO

This paper investigates an adaptive threshold decision (ATD) scheme without the knowledge of channel state information (CSI) for optical wireless communication (OWC). Based on the low-pass characteristic of atmospheric turbulence channels, a low-pass filter is designed for the received signals, and the filtered signal can be employed as decision threshold. Theoretical analyses show that performance of ATD is very close to that with perfect CSI. Monte Carlo simulations demonstrate that the proposed scheme shows only 0.0221dB signal-to-noise (SNR) loss at most with Rytov variance of 0.05 and SNR of 21dB. An indoor experiment results are presented, which match well with that of theoretical prediction. The scheme is simple and without CSI, hence the efficient scheme makes the real-time implementation of high-speed transmissions for OWC based on ATD feasible.

16.
J Opt Soc Am A Opt Image Sci Vis ; 34(5): 798-803, 2017 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-28463323

RESUMO

This paper investigates a detection scheme without channel state information for wireless optical communication systems. Employing conventional on-off keying signals, we supposed that conditional probability density function P(r|0) is much bigger than P(r|1) when r<0. Under this assumption, the suboptimal maximum likelihood scheme is obtained by utilizing the probability density function without channel information. Theoretical analysis shows the performance of the proposed scheme is close to the maximum likelihood symbol-by-symbol detection. Compared with the maximum likelihood symbol by symbol detection, Monte Carlo simulations show that the performance of the proposed scheme is about 0.62 dB loss for a gamma-gamma channel with a Rytov variance of 1 at the signal-to-noise ratio of 2 dB, but the efficient algorithm makes the real-time implementation of detection based on maximum likelihood feasible. Besides, the experiment is set up under 2 Gbps, and the experimental results match well with that of the theory and simulation.

17.
Appl Opt ; 56(18): 5145-5155, 2017 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29047565

RESUMO

We theoretically analyze and experimentally verify the performance of multiple polarization parameters in the presence of atmospheric turbulence for a terrestrial optical transmission. First, both the first- and second-moment characteristic of polarization parameters are derived based on the extended Huygens-Fresnel principle. Then, numerical simulations are presented for different propagating distances, optical source properties, and turbulent strengths. Finally, a series of well-designed experiments are carried out to verify the theory with turbulence-controlled conditions, where the polarization states are measured at two wavelengths, respectively. As a result, the theoretical predictions conform closely to the experimental data, and both show that with the increasing turbulent strength, the first-order moment of polarization parameters varies in different trends, while their second-order moment increases. The proposed approach is promising for building a comprehensive statistical model of polarization and improving the performance of a free-space optical communication link.

18.
J Sep Sci ; 39(20): 4027-4034, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27569853

RESUMO

An efficient and easy sample pretreatment methodology was proposed for the detection of photoinitiator 4-methylbenzophenone from milk before high-performance liquid chromatography. Appropriate conditions for demulsification were studied. The parameters affecting cloud point extraction, such as concentration of Tween-20, electrolyte salt, equilibration temperature, and time, have been investigated. When the spiked level was 200-1000 µg/kg, the average addition standard recovery was 99.14-105.98% with the optimum cloud point extraction conditions (concentration of Tween-20, 138 g/L; mass of anhydrous sodium sulfate, 0.75 g; equilibration temperature, 65°C; equilibration time, 30 min). To decrease the detection limits, further work about the organic solvent, shaking time, and ultrasonic parameters was carried. When the spiked level was 10-100 µg/kg, the average addition standard recovery was 70.40-106.91% with the optimum cloud point extraction and enrichment conditions (optimum cloud point extraction conditions; volume of cyclohexane, 30 mL; shaking time, 20 min; time of ultrasonic, 20 min; temperature of ultrasonic bath, 45°C).


Assuntos
Benzofenonas/análise , Leite/química , Animais , Fracionamento Químico , Cromatografia Líquida de Alta Pressão , Ultrassom
19.
Opt Express ; 22(26): 32482-8, 2014 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-25607210

RESUMO

In wireless optical communications (WOC), polarization multiplexing systems and coherent polarization systems have excellent performance and wide applications, while its state of polarization affected by atmospheric turbulence is not clearly understood. This paper focuses on the polarization fluctuations caused by atmospheric turbulence in a WOC link. Firstly, the relationship between the polarization fluctuations and the index of refraction structure parameter is introduced and the distribution of received polarization angle is obtained through theoretical derivations. Then, turbulent conditions are adjusted and measured elaborately in a wide range of scintillation indexes (SI). As a result, the root-mean-square (RMS) variation and probability distribution function (PDF) of polarization angle conforms closely to that of theoretical model.


Assuntos
Atmosfera/química , Modelos Teóricos , Dispositivos Ópticos , Refratometria/instrumentação , Telecomunicações/instrumentação , Tecnologia sem Fio/instrumentação , Simulação por Computador , Luz , Dinâmica não Linear , Espalhamento de Radiação
20.
Microbiol Res ; 282: 127657, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38422862

RESUMO

Halophytes inhabit saline soils, wherein most plants cannot grow, therefore, their ecological value is outstanding. Arbuscular mycorrhizal (AM) fungi can reconstruct microbial communities to assist plants with stress tolerance. However, little information is available on the microbial community assembly of AM fungi in halophytes. A pot experiment was conducted to investigate the effects of AM fungi on rhizosphere bacterial community structure and soil physiochemical characteristics in the halophyte Suaeda salsa at 0, 100, and 400 mM NaCl. The results demonstrated that AM fungi increased soil alkaline phosphatase (ALP) activity at the three NaCl concentrations, and decreased available P, available K, and the activity of soil catalase (CAT) at 100 mM NaCl. AM fungi decreased the Shannon index of the community at 0 and 100 mM NaCl and increased Sobs index at 400 mM NaCl. Regarding the bacterial community structure, AM fungi substantially decreased the abundance of Acidobacteria phylum at 0 and 100 mM NaCl. AM fungi significantly increased the abundance of genus Ramlibacter, an oxyanion-reducing bacteria that can clean out reactive oxygen species (ROS). AM fungi recruited the genera Massilia and Arthrobacter at 0 and 100 mM NaCl, respectively. Some strains in the two genera have been ascribed to plant growth promoting bacteria (PGPB). AM fungi increased the dry weight and promoted halophyte growth at all three NaCl levels. This study supplements the understanding that AM fungi assemble rhizosphere bacterial communities in halophytes.


Assuntos
Chenopodiaceae , Micorrizas , Plantas Tolerantes a Sal , Cloreto de Sódio , Fungos , Bactérias/genética , Solo/química , Microbiologia do Solo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA